1. Field of the Invention
The present invention relates to a high frequency wave glass antenna for an automobile which is suitable for receiving a radiowave having a wavelength of 300 MHz to 3 GHz (UHF band) and is excellent in the receiving sensitivity.
2. Discussion of Background
There is the Global Positioning System (GPS) using artificial satellites as a means for detecting the position of an automobile.
Concerning an antenna for the GPS satellites, a GPS antenna of a micro strip antenna has already been on sale which is formed with conductor layers on the surface and on the rear face of a dielectric substrate as an antenna conductor and a grounding conductor, and a receiving signal excited between the antenna conductor and the grounding conductor is amplified by a preamplifier circuit.
This conventional GPS antenna has been employed it on a roof or on a trunk of an automobile by a magnet attached to a case, or by a fixture, or by fixing it in the interior side of a glass window of an automobile in the vicinity of an opening portion of the automobile such as a window by a method of screwing or the like. However, the conventional GPS antenna is too large, and is unattractive when installed on the roof or on the trunk. Further, there is a danger of robbery. An aging deterioration is caused since it is installed outside of an automobile.
Further, even when the antenna is installed on the interior of a glass window of an automobile in the vicinity of a window of an automobile, a wide space is necessary for attaching it. Therefore the viewing angle is narrowed when the window of an automobile through which a radiowave is transmitted into the car room, is viewed from the attaching position and the receiving range is also narrowed.